Ground rod



June 18, 1935. w. J. MOILVANE GROUND ROD Filed Aug. 24, 1932 PatentedJune 18,1935

UNITED STATES PATENT OFFICE GROUND ROD William J. McIlvane, Bellerose,N. Y., assignor to Bridgeport Brass Company, Bridgeport, Conn., acorporation of Connecticut Application August 24, 1932, Serial No.630,202

Claims. (01. 173-31) This invention relates to ground rods used for Fig.4 is a top plan view of the parts shown in grounding electricalapparatus. Customarily, Fig. 3; such rods are driven into the earth toprovide Fig. 5 is an edge view of the structure shown electrical groundsfor lightning arresters, radio in Fig. 3;

i5 circuits, transformer cases, and other electrical Fig. 4a shows theclamping block illustrated in 5 apparatus d i t, Fig. 4 but with thetransverse bolt and side In providing a ground rod or ground electrodeclamping plates omitted and with a lead wire which would be long-livedand would not be subclamped to the front edge portion of the block; jectto attack by corrosion, it has been considered Fig. 6 is a sideelevation of a still further modi- 1 necessary in many cases to make therod itself fied form; and 10 of copper, or steel covered with copper.With Fig. 7 is a top plan view of the parts shown in such a rod, it waspossible to connect the copper Fig. 6. lead wires to therod body havingan outer sur- It is understood from what has been said above face ofcopper without causing corrosion due to that in the practice of myinvention, the ground galvanic action between the rod and the wires or rd pr p r i pr f r y n ru d f Wr ht 15 parts th n However, copper d d tha iron or other ferrous material; that the lead wire the necessaryrigidity to be driven into hard Wires are preferably made of pper 0Other earth, and steel rods covered with copper have non-ferrous m t andhat it is aimed to probeen wh t im it, expensive t produce, vide astructure for connecting the lead wire or one of the objects of myinvention is to prowires to the IOd in a manner which is simple and 20 da tr t h h permits th enlplgyconvenient and which overcomes the settingup ment of a. rod proper made of wrought iron, so of a van c action inthe structure.

that the rod may be 'suificiently strong and rigid In the form Shown in1 a e OImd and may at the same time be relativelyinexrod prop h h is i ad t m y e aspensive "and have very satisfactory resistance to sumed tobe a long p d d of Wrought iron. 25 underground corrosion, which is acondition real- T this od is connected a substantially c g ized veryefiectively when the rod is made of clamping block ll of 1 1 y e s ofpuddled iron, for example. However, my imwhich the copper lead Wires 1 2are connected elecprovements are not limited to the use of wroughttrically With the irOIl The pp block l 3o m as t rod proper may b d fcopperis preferably grooved at one side, as indicated at bearing steelor other alloy steel or iron which 50 as t0 Conform to the Curvature Ofth 0Y- resists underground corrosion. lindrical electrode body, andwhere the block con- Another object of my invention is to provide ormsto the electrode body, it is secured thereto a non -corrodingconstruction in which the lead by a Corrosion-proof J'O Such as p d ywire or wires can be effectively clamped to the Welding, z Soldering,wis Derma- 35 'rod by a. releasable mechanical clamp of Simple nentlysecuring the blocli to the rod. In the parnature. It is intended tprovide a device which miller form shown In Flgs- 1 and 2, ground Wiresis very convenient in use and yet relatively inexmay attached 9 the m atOpposlte sldes pensive thereof1 lslg that1 wires ltlllinilzllitlpll;cafi be; cotnniectted 40 Another object is to provide means for connect-0 gm r c S 1 e W0 i to iiiiiii t: eat ries? grains; are:ferrousgrandmas-1reslmpleaneeeeemmenblock throughout the height of theblock, and ner andwith the avo dance of galvanic corrosion.

I betweenthese grooves is located a bore IE to i To these and otherends,the invention consists receive a clamping bolt '5 having a head n on 45in the novel features and combinations of parts one end and a nut l8engaging threads on the to be ere a described and Claimedopposite end ofthe bolt shank. Round copper In the d w washers I 8 may be employed forclamping the g Fig. 1 is a side elevation of a ground rod conwires tothe faces of the block in an obvious 59 structed iniaccordance with myinvention; manner.

Fig. 2 is atop plan view of the parts shown in In the form shown inFigs. 3, 4, 4a and 5, the .Fig. 1; 7 f structure is modified in someparticulars. In Fig. 3 is a side elevation of a modified structure thisinstance, the block 20, instead of having in which approximatelyrectangular wire clampgrooved side faces, has plain flat side faces, and

65 ing plates are employed; wires are clamped against it and heldagainst lateral dislocation by substantially rectangular clamping plates2| of copper having grooved side portions 22 which engage the lead wiresand in turn are engaged by round copper washers 23. One of the washers23 is located beneath the head Ila of bolt "a, and the other washer islocated in engagement with a nut i8a. engaging the threaded shank ofbolt IGa.

In this second form, a lead wire may be secured to the front or outeredge of the clamping block, if this is desired. In such case, theremovable clamping devices shown in Fig. 4 are taken off the block, anda small clamping plate 24 is secured in position at the front face ofthe block by the small bolt 25 having a threaded shank engaging athreaded socket'26 in the clamping block, as shown in Fig. 4a. In thiscase the lead wire He is held in place by plate 24 in a groove 21 at thefront edge of the block, a shown more particularly in Fig. 5. I

It will be understood that in the constructions so far described, thecopper or similar non-ferrous clamping block is attached to the ferrousrod in a manner which prevents the setting up of galvanic action betweenthe block and the rod;

contacts with rod I0 is made of the same material as said rod, it canhave a releasable clamping engagement with said rod. Thus, in theparticular form shown, the ferrous attaching plate 28 has formedintegral with it a ferrous sleeve member 29 adapted to be slid along rod[0 and to be held in the desired position thereon by means of ferrousset screw 30. At opposite faces of plate 28, non-ferrous plates 3| aresecured thereto in a manner which provides against the setting up ofgalvanic action, for example, by welding, brazing or soldering members3| to member 28, thus forming a composite clamping block. The members 3|are provided with grooves 32 similar to the grooves l4 previouslydescribed, and the, non-ferrous ground wires l2b are releasably held inthese grooves by means similar to those described with reference to thestructure shown in Figs. 1 and 2. The structure shown in Figs. 6 and 7is, in fact, similar to that shown in Figs. land 2, the principaldifierence being that in the former arrangement a ferrous supportingframe for the clamping block is employed, such frame having releasablemechanical engagement with the body of the electrode.

While I have illustrated and described several embodiments of myinvention, I have not attempted to describe all of the different formswhich may be taken by the invention without departure from theprinciples of my invention as defined in the claims.

What I claim is:

1. In a device for connecting electrical apparatus to ground, thecombination of a ground rod body adapted to be driven into the ground,said body being made of ferrous material and resistant to bending, aclamping block located adjacent the upper end of the rod body andextending parallel to said body in the plane thereof and presentededgewise to said body and curved to conform to the periphery thereof,said block having at the side face thereof a non-ferrous surface adaptedto be engaged by ground wires for preventing electrolysis, means ofconnection between the edge portion only of said block and the rod bodyfor securing the block to the rod body in rigid relation thereto, aclamping member of non-ferrous material located at one of the side facesof said block and adapted to clamp ground wires against said block, anda bolt extending into said block and clamping member for holding saidclamping member in clamping relation to the wires.

2. In a device for connecting electrical apparatus to ground, thecombination of a ground rod body adapted to be driven into the ground, aclamping block located adjacent the upper end of the rod body andextending parallel to said body in the plane thereof and presentededgewise to said body and shaped to conform to the periphery thereof,said block having at the side face thereof a surface of a differentmetal from that of the rod body adapted to be engaged by ground wiresfor preventing electrolysis, means of connection between the edgeportion only of said block and the rod body for securing the block tothe rod body in rigid relation thereto, a clamping member located at oneof the side faces of said block and adapted to clamp ground wiresagainst said block, and a bolt extending into said block and clampingmember for holding said clamping member in clamping relation to thewires.

3. In a device for connecting electrical apparatus to ground, thecombination of a solid ground rod of round cross section adapted to bedriven into the ground, a substantially rectangular clamping block of athickness approximating the diameter of the rod body located adjacentthe upper end of the rod body and presented edgewise thereto so as tolie in the plane of the rod body, said block being in abutting relationto the rod body and curved to conform to the periphery thereof, saidblock having side faces of a different metal from that of the ground rodbody adapted to be engaged by ground wires, means for securing the blockrigidly to the rod body, said block having a hole extending horizontallytherethrough between the rod body and the outer edge of said block,clamping members at the side faces of said block, and a bolt passingthrough said hole for holding said clamping members in clamping relationto said block, the clamping parts intermediate the bolt and the rod bodybeing provided with vertical wire-receiving grooves located at the sidefaces of the block and there being similar wire-receiving grooves atthat side of the bolt which is remote from the rod body.

4. In a device for connecting electrical conductors to ground, thecombination of a solid continuous ground rod body adapted to be driveninto the ground and of substantially uniform round cross-sectionthroughout the major part of its length, a clamping block ofsubstantially rectangular shape extending parallel to the rod body andpresented edgewise thereto so as to lie in the plane of said body, saidblock being of a thickness approximating the diameter of the rod bodyand having a curved edge portion presented and conforming to the rodbody, means of integral connection between the curved edge of said blockand said rod body whereby said block is rigidly and intimately connectedwith said body, a side face of said block being adapted to engage one ormore electrical conductors and being of a diiferent metal from saidground rod body and of a similar metal to the conductors, for preventingelectrolysis, a clamping member located at said side face of said blockand adapted to clamp the conductors against said face, and a bolt insaid block and said clamping member for holding said clamping member inclamping relation to the conductors.

5. In a ground rod structure, a ground rod body of ferrous material andof solid round cross-section, a, non-ferrous clamping blocksubstantially rectangular in shape located adjacent the upper end of therod body and extending parallel to said body and presented edgewisethereto so as to lie in the plane thereof, said block being of athickness approximating the diameter of the rod body and having a curvededge portion presented to the rod body, means of intimate connectionbetween the curved edge portion of said block and the rod body forsecuring the block to the rod body in rigid integral relation thereto,clamping members of non-ferrous material at the side faces of saidblock, and a bolt extending through a hole in said block and adapted tohold the clamping members in clamping relation to vertical wiresinterposed between the clamping members and the block, the clampingportions being provided with vertical wire-receiving grooves, certain ofsaid grooves being between the bolt and the rod body and others being atthe remote side of the bolt.

WILLIAM J. McILVANE.

